Biology

Antibiotics and Immunity

974 Questions

Prepare for your science sections with these questions on antibiotics and immunity. The hub covers various classes of antibiotics, their sources, and mechanisms of microbial resistance. It also addresses the human antiviral response.

Antibiotic classes and sourcesMicrobial resistance mechanismsAntiviral proteinsDisease treatments

Antibiotics and Immunity Questions

Multiple choice biology classification of plants monera five kingdoms of living organisms biodiversity and need of classification

Bacteria having comma-like single curve in their body are

  1. Bacilli

  2. Cocci

  3. Vibrio

  4. Spirilla
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria having rod shaped structure are called as Bacilli. Examples include Clostridium tetani, Corynebacterium. Bacteria that are round in shape are called as cocci. Examples include Streptococcus pneumoniae, Staphylococcus aureus. Bacteria having comma-like single curve in their body are Vibrio. Examples include Vibrio cholerae, Vibrio vulnificus. Bacteria having spiral shape are called as Spirilla. Examples include Spirillum, Campylobacter.

Thus, the correct answer is 'Vibrio.'

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

Anticoagulant substance in endospore of bacteria is found in 

  1. Exosporium and spore coat

  2. Spore coat and cortex

  3. Cortex and core wall

  4. Cortex and cytoplasm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Endospore of bacteria is mainly covered with three extra layers: 

Exosporium, spore coat and cortex.
Exosporium and spore coat are made of proteins, whereas cortex is made of modified peptidoglycans. Peptidoglycans are coagulants.
Proteins are anticoagulants hence found in exosporium and spore coat.
So the correct answer is ' Exosporium and spore coat'. 

Multiple choice biology classification of plants monera five kingdoms of living organisms biodiversity and need of classification

Which of the following differentiates gram positive and gram negative bacteria?

  1. A liposaccharide, outer covering with a small peptidoglycan component in the cell wall

  2. A small peptidoglycan, component covering a large liposaccharide base

  3. A large peptidoglycan, component in the cell wall

  4. A cell wall composed of liposaccharide and chitin

  5. A cell wall composed of chitin over peptidoglycan
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The gram-negative cell wall is characterized by presence of outer membrane, a thinner peptidoglycan layer and extensive periplasmic space surrounding the peptidoglycan. The uppermost layer of the outer membrane has lipopolysaccharide while the innermost layer is a typical lipid layer. Gram positive cells are characterized by presence of single thick layer of cell wall which is made up of peptidogycan, teichoic acid and lipoteichoic acid. They lack outer membrane and porin and have narrow periplasmic space. Correct answer is C.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Some bacteria have a capsule outside cell wall. It is made of

  1. Protein

  2. Cellulose

  3. Fat

  4. Mucopolysaccharide
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Some bacteria have a capsule outside cell wall. It is made up of mucopolysaccharide. The functions of mucopolysaccharide are;

  • It enhances the ability of bacteria to cause disease. 
  • It protects cells from engulfment by macrophages. 
  • It protects cells from desiccation.
Thus, the correct answer is 'Mucopolysaccharide.'

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Superbugs are

  1. Synthetic bug

  2. Bacteria

  3. Radio nucleotide

  4. Industries
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Superbugs is a term used to describe strains of bacteria that are resistant to the majority of antibiotics commonly used today. These resistant bacteria can cause pneumonia, urinary tract infections, skin infections and many other diseases that are difficult to treat and may be fatal.

So, the correct answer is 'Bacteria'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Peptidoglycan forms many layers in the wall of

  1. Gram $(+)$ bacteria
  2. Gram $(-)$ bacteria

  3. Gram neutral bacteria

  4. All the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

On the basis of composition of cell wall, the bacteria are classified into two groups, namely Gram positive and Gram negative bacteria. Cell wall of all bacteria is made up of peptidoglycan. The gram positive bacteria contains many layers of peptidoglycan. However, Gram negative bacteria contains single layer of peptidoglycan. Apart from this, it also contains an outer layer of lipopolysaccharide (LPS). 

Thus, the correct answer is 'Gram (+) bacteria.'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Gram positive bacteria are more rigid than Gram negative bacteria because of the 

  1. presence of multiple layers of peptidoglycan

  2. lack of D-amino acids in their cell wall

  3. presence of N-acetylgalactosamine in the peptidoglycan backbone

  4. presence of lipopolysaccharide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Because gram-positive bacteria are surrounded by layers of peptidoglycan which is many times thicker than is found in the gram negatives. Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which is surrounded by an outer membrane containing lipopolysaccharide which is not present in gram-positive bacteria.

So, the correct answer is 'presence of multiple layers of peptidoglycan'.
Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

Teichoic acid is present in 

  1. Gram +ve bacteria

  2. Gram -ve bacteria

  3. Spirochaete

  4. Actinomycetes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Teichoic acids are found within the cell wall of Gram-positive bacteria. The main function of teichoic acid is to provide rigidity to the cell wall by attracting cations, such as magnesium and sodium.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Difference in Gram +ve  and Gram -ve bacteria is due to

  1. Cell wall

  2. Cell membrane

  3. Ribosome

  4. Cytoplasm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cell wall of certain bacteria shows a characteristic reaction to the stain devised by C. Gram. Those bacteria which retain the stain are known as Gram positive and those which do not retain the stain are called Gram negative.

  • The cell wall in bacteria contains peptidoglycan, a polymer of N-acetyl glucosamine, N-acetyl muramic acid and amino acids.
  • Gram-positive cell walls contain a thick layer of peptidoglycan that encircles the cell.
  • Gram-negative cell walls contain a thin layer of peptidoglycan between the cytoplasmic membrane and the outer membrane.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Gram-negative bacteria that cause infections, when stained,  do not retain the crystal violet stain, which tells the researcher that

  1. The peptidoglycan layer is thick and the bacteria are resistant to antibiotics.

  2. The peptidoglycan layer is very thin and the bacteria is susceptible to antibiotics.

  3. The peptidoglycan layer is very thin and the bacteria are resistant to antibiotics.

  4. The peptidoglycan layer contains an impermeable lipid layer.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The peptidoglycan layer of the gram negative bacteria are thin and are also referred to as the cell envelope. The layer is wavy and provides resistance to antibiotics. They are more virulent as compared to Gram positive bacteria

So, the correct answer is 'The peptidoglycan layer is very thin and the bacteria are resistant to antibiotics'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

One of the following is less resistant or more susceptible to antibiotics.

  1. Gram positive bacteria

  2. Gram negative bacteria

  3. Escherichia coli

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gram-negative bacteria have a unique outer membrane. This outer membrane prevents penetration of antibiotics within the cell. However, Gram-positive bacteria do not have an outer LPS membrane. This makes them more susceptible or less resistant to antibiotics than gram-positive bacteria.

Thus, the correct answer is 'Gram-positive bacteria.'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Streptomycin is effective against .......... bacteria

  1. Gram $(+)$
  2. Gram $(-)$

  3. Gram neutral
  4. Both Gram $(+)$ and Gram $(-)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Streptomycin is an antibiotic which is used in the treatment of bacterial infections. It belongs to the Aminoglycoside antibacterial class. It is a broad-spectrum antibiotic. It is effective against both Gram-positive and Gram-negative bacteria. It is used in the treatment of tuberculosis, endocarditis, plague, rat bite fever. 

Thus, the correct answer is 'Both Gram (+) and Gram (−).'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Which one occurs in the cell walls of Gram (+) bacteria only?

  1. Peptidoglycan

  2. Lipopolysaccharide

  3. Teichoic acid

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Teichoic acids are found within the cell wall of most Gram-positive bacteria such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium, and Listeria, and appear to extend to the surface of the peptidoglycan layer.

So, C is the correct option.